Publications


Neutrino oscillation studies with IceCube-DeepCore

Nuclear Physics B 908 (2016) 161-177

MG Aartsen, K Abraham, M Ackermann, J Adams, JA Aguilar, M Ahlers, M Ahrens, D Altmann, T Anderson, I Ansseau, M Archinger, C Arguelles, TC Arlen, J Auffenberg, X Bai, SW Barwick, V Baum, R Bay, JJ Beatty, J Becker Tjus, KH Becker, E Beiser, P Berghaus, D Berley, E Bernardini, A Bernhard, DZ Besson, G Binder, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, M Börner, F Bos, D Bose, S Böser, O Botner, J Braun, L Brayeur, HP Bretz, N Buzinsky, J Casey, M Casier, E Cheung, D Chirkin, A Christov, K Clark, L Classen, S Coenders, GH Collin, JM Conrad, DF Cowen, AH Cruz Silva, J Daughhetee, JC Davis, M Day, JPAM de André, C De Clercq, E del Pino Rosendo, H Dembinski, S De Ridder, P Desiati, KD de Vries, G de Wasseige, M de With, T DeYoung, JC Díaz-Vélez, V di Lorenzo, JP Dumm, M Dunkman, B Eberhardt, T Ehrhardt, B Eichmann, S Euler, PA Evenson, S Fahey, AR Fazely, J Feintzeig, J Felde, K Filimonov, C Finley, S Flis, CC Fösig, T Fuchs, TK Gaisser, R Gaior, J Gallagher, L Gerhardt, K Ghorbani, D Gier, L Gladstone, M Glagla, T Glüsenkamp, A Goldschmidt

© 2016 Elsevier B.V.IceCube, a gigaton-scale neutrino detector located at the South Pole, was primarily designed to search for astrophysical neutrinos with energies of PeV and higher. This goal has been achieved with the detection of the highest energy neutrinos to date. At the other end of the energy spectrum, the DeepCore extension lowers the energy threshold of the detector to approximately 10 GeV and opens the door for oscillation studies using atmospheric neutrinos. An analysis of the disappearance of these neutrinos has been completed, with the results produced being complementary with dedicated oscillation experiments. Following a review of the detector principle and performance, the method used to make these calculations, as well as the results, is detailed. Finally, the future prospects of IceCube-DeepCore and the next generation of neutrino experiments at the South Pole (IceCube-Gen2, specifically the PINGU sub-detector) are briefly discussed.


Footprints of Loop i on Cosmic Microwave Background maps

Journal of Cosmology and Astroparticle Physics 2016 (2016)

SV Hausegger, H Liu, P Mertsch, S Sarkar

© 2016 IOP Publishing Ltd and Sissa Medialab srl .Cosmology has made enormous progress through studies of the cosmic microwave background, however the subtle signals being now sought such as B-mode polarisation due to primordial gravitational waves are increasingly hard to disentangle from residual Galactic foregrounds in the derived CMB maps. We revisit our finding that on large angular scales there are traces of the nearby old supernova remnant Loop I in the WMAP 9-year map of the CMB and confirm this with the new SMICA map from the Planck satellite.


High Orbital Angular Momentum Harmonic Generation

Physical Review Letters 117 (2016)

J Vieira, RMGM Trines, EP Alves, RA Fonseca, JT Mendonça, R Bingham, P Norreys, LO Silva

© 2016 American Physical Society.We identify and explore a high orbital angular momentum (OAM) harmonics generation and amplification mechanism that manipulates the OAM independently of any other laser property, by preserving the initial laser wavelength, through stimulated Raman backscattering in a plasma. The high OAM harmonics spectra can extend at least up to the limiting value imposed by the paraxial approximation. We show with theory and particle-in-cell simulations that the orders of the OAM harmonics can be tuned according to a selection rule that depends on the initial OAM of the interacting waves. We illustrate the high OAM harmonics generation in a plasma using several examples including the generation of prime OAM harmonics. The process can also be realized in any nonlinear optical Kerr media supporting three-wave interactions.


Modelling Lyman a forest cross-correlations with LyMAS

Monthly Notices of the Royal Astronomical Society 461 (2016) 4353-4373

C Lochhaas, DH Weinberg, S Peirani, Y Dubois, S Colombi, J Blaizot, A Font-Ribera, C Pichon, J Devriendt

© 2016 The Authors.We use the Lya Mass Association Scheme (LyMAS) to predict cross-correlations at z = 2.5 between dark matter haloes and transmitted flux in the Lya forest, and compare to crosscorrelations measured for quasars and damped Lya systems (DLAs) from the Baryon Oscillation Spectroscopic Survey (BOSS) by Font-Ribera et al. We calibrate LyMAS using Horizon-AGN hydrodynamical cosmological simulations of a (100 h -1 Mpc)3 comoving volume. We apply this calibration to a (1 h -1 Gpc)3 simulation realized with 20483 dark matter particles. In the 100 h -1 Mpc box, LyMAS reproduces the halo-flux correlations computed from the full hydrodynamic gas distribution very well. In the 1 h -1 Gpc box, the amplitude of the large-scale cross-correlation tracks the halo bias bh as expected. We provide empirical fitting functions that describe our numerical results. In the transverse separation bins used for the BOSS analyses, LyMAS cross-correlation predictions follow linear theory accurately down to small scales. Fitting the BOSS measurements requires inclusion of random velocity errors; we find best-fitting rms velocity errors of 399 and 252 km s-1 for quasars and DLAs, respectively. We infer bias-weighted mean halo masses of Mh/1012 h-1M⊙ = 2.19+0.16-0.15 and 0.69+0.16-0.14 for the host haloes of quasars and DLAs, with ~0.2 dex systematic uncertainty associated with redshift evolution, intergalactic medium parameters, and selection of data fitting range.


All-flavour search for neutrinos from dark matter annihilations in the Milky Way with IceCube/DeepCore

European Physical Journal C 76 (2016)

MG Aartsen, K Abraham, M Ackermann, J Adams, JA Aguilar, M Ahlers, M Ahrens, D Altmann, K Andeen, T Anderson, I Ansseau, G Anton, M Archinger, C Arguelles, TC Arlen, J Auffenberg, S Axani, X Bai, SW Barwick, V Baum, R Bay, JJ Beatty, J Becker Tjus, KH Becker, S BenZvi, P Berghaus, D Berley, E Bernardini, A Bernhard, DZ Besson, G Binder, D Bindig, M Bissok, E Blaufuss, S Blot, DJ Boersma, C Bohm, M Börner, F Bos, D Bose, S Böser, O Botner, J Braun, L Brayeur, HP Bretz, A Burgman, J Casey, M Casier, E Cheung, D Chirkin, A Christov, K Clark, L Classen, S Coenders, GH Collin, JM Conrad, DF Cowen, AH Cruz Silva, J Daughhetee, JC Davis, M Day, JPAM de André, C De Clercq, E del Pino Rosendo, H Dembinski, S De Ridder, P Desiati, KD de Vries, G de Wasseige, M de With, T DeYoung, JC Díaz-Vélez, V di Lorenzo, H Dujmovic, JP Dumm, M Dunkman, B Eberhardt, T Ehrhardt, B Eichmann, S Euler, PA Evenson, S Fahey, AR Fazely, J Feintzeig, J Felde, K Filimonov, C Finley, S Flis, CC Fösig, A Franckowiak, T Fuchs, TK Gaisser, R Gaior, J Gallagher, L Gerhardt, K Ghorbani

© The Author(s) 2016.We present the first IceCube search for a signal of dark matter annihilations in the Milky Way using all-flavour neutrino-induced particle cascades. The analysis focuses on the DeepCore sub-detector of IceCube, and uses the surrounding IceCube strings as a veto region in order to select starting events in the DeepCore volume. We use 329 live-days of data from IceCube operating in its 86-string configuration during 2011–2012. No neutrino excess is found, the final result being compatible with the background-only hypothesis. From this null result, we derive upper limits on the velocity-averaged self-annihilation cross-section, ⟨ σAv ⟩ , for dark matter candidate masses ranging from 30 GeV up to 10 TeV, assuming both a cuspy and a flat-cored dark matter halo profile. For dark matter masses between 200 GeV and 10 TeV, the results improve on all previous IceCube results on ⟨ σAv ⟩ , reaching a level of 10- 23 cm3 s- 1, depending on the annihilation channel assumed, for a cusped NFW profile. The analysis demonstrates that all-flavour searches are competitive with muon channel searches despite the intrinsically worse angular resolution of cascades compared to muon tracks in IceCube.


Scaled laboratory experiments explain the kink behaviour of the Crab Nebula jet.

Nat Commun 7 (2016) 13081-

CK Li, P Tzeferacos, D Lamb, G Gregori, PA Norreys, MJ Rosenberg, RK Follett, DH Froula, M Koenig, FH Seguin, JA Frenje, HG Rinderknecht, H Sio, AB Zylstra, RD Petrasso, PA Amendt, HS Park, BA Remington, DD Ryutov, SC Wilks, R Betti, A Frank, SX Hu, TC Sangster, P Hartigan, RP Drake, CC Kuranz, SV Lebedev, NC Woolsey

The remarkable discovery by the Chandra X-ray observatory that the Crab nebula's jet periodically changes direction provides a challenge to our understanding of astrophysical jet dynamics. It has been suggested that this phenomenon may be the consequence of magnetic fields and magnetohydrodynamic instabilities, but experimental demonstration in a controlled laboratory environment has remained elusive. Here we report experiments that use high-power lasers to create a plasma jet that can be directly compared with the Crab jet through well-defined physical scaling laws. The jet generates its own embedded toroidal magnetic fields; as it moves, plasma instabilities result in multiple deflections of the propagation direction, mimicking the kink behaviour of the Crab jet. The experiment is modelled with three-dimensional numerical simulations that show exactly how the instability develops and results in changes of direction of the jet.


Simulated observations of high-redshift galaxies with the HARMONI spectrograph for the European Extremely Large Telescope

Proceedings of SPIE - The International Society for Optical Engineering 9908 (2016)

S Kendrew, S Zieleniewski, RCW Houghton, N Thatte, J Devriendt, M Tecza, F Clarke, K O'Brien, B Häußler

© 2016 SPIE.We show the results of a study into the performance of the E-ELT integral field spectrograph HARMONI for observations of galaxies at 2 < z < 4. Using the instrument simulation pipeline HSIM, we performed mock observations of galaxies in this redshift range using two different methods: (i) passive galaxies modeled with simple analytical spatial profiles and star formation histories; and (ii) a single z = 3 galaxy extracted from a high-resolution cosmological simulation, with a more complex and physically representative morphology and star formation history. We describe the software tools developed to convert the simulation data into a spectral cube containing the spatial and spectral properties of the galaxy's light. From the mock observations we estimate how well the intrinsic properties of the galaxy can be recovered using commonly used analysis tools. The HSIM pipeline also allows us to study observational biases and their likely impact on the data. We discuss the implications of the project for the future science with HARMONI in the critical redshift regime for mass assembly in galaxies.


The XXL Survey: I. Scientific motivations - XMM-Newton observing plan - Follow-up observations and simulation programme

Astronomy and Astrophysics 592 (2016)

M Pierre, F Pacaud, C Adami, S Alis, B Altieri, N Baran, C Benoist, M Birkinshaw, A Bongiorno, MN Bremer, M Brusa, A Butler, P Ciliegi, L Chiappetti, N Clerc, PS Corasaniti, J Coupon, C De Breuck, J Democles, S Desai, J Delhaize, J Devriendt, Y Dubois, D Eckert, A Elyiv, S Ettori, A Evrard, L Faccioli, A Farahi, C Ferrari, F Finet, S Fotopoulou, N Fourmanoit, P Gandhi, F Gastaldello, R Gastaud, I Georgantopoulos, P Giles, L Guennou, V Guglielmo, C Horellou, K Husband, M Huynh, A Iovino, M Kilbinger, E Koulouridis, S Lavoie, AMC Le Brun, JP Le Fevre, C Lidman, M Lieu, CA Lin, A Mantz, BJ Maughan, S Maurogordato, IG McCarthy, S McGee, JB Melin, O Melnyk, F Menanteau, M Novak, S Paltani, M Plionis, BM Poggianti, D Pomarede, E Pompei, TJ Ponman, ME Ramos-Ceja, P Ranalli, D Rapetti, S Raychaudury, TH Reiprich, H Rottgering, E Rozo, E Rykoff, T Sadibekova, J Santos, JL Sauvageot, C Schimd, M Sereno, GP Smith, V Smolčić, S Snowden, D Spergel, S Stanford, J Surdej, P Valageas, A Valotti

© ESO, 2016.Context. The quest for the cosmological parameters that describe our universe continues to motivate the scientific community to undertake very large survey initiatives across the electromagnetic spectrum. Over the past two decades, the Chandra and XMM-Newton observatories have supported numerous studies of X-ray-selected clusters of galaxies, active galactic nuclei (AGNs), and the X-ray background. The present paper is the first in a series reporting results of the XXL-XMM survey; it comes at a time when the Planck mission results are being finalised. Aims. We present the XXL Survey, the largest XMM programme totaling some 6.9 Ms to date and involving an international consortium of roughly 100 members. The XXL Survey covers two extragalactic areas of 25 deg2 each at a point-source sensitivity of ∼5 × 10-15 erg s-1 cm-2 in the [0.5-2] keV band (completeness limit). The survey's main goals are to provide constraints on the dark energy equation of state from the space-time distribution of clusters of galaxies and to serve as a pathfinder for future, wide-area X-ray missions. We review science objectives, including cluster studies, AGN evolution, and large-scale structure, that are being conducted with the support of approximately 30 follow-up programmes. Methods. We describe the 542 XMM observations along with the associated multi-λ and numerical simulation programmes. We give a detailed account of the X-ray processing steps and describe innovative tools being developed for the cosmological analysis. Results. The paper provides a thorough evaluation of the X-ray data, including quality controls, photon statistics, exposure and background maps, and sky coverage. Source catalogue construction and multi-λ associations are briefly described. This material will be the basis for the calculation of the cluster and AGN selection functions, critical elements of the cosmological and science analyses. Conclusions. The XXL multi-λ data set will have a unique lasting legacy value for cosmological and extragalactic studies and will serve as a calibration resource for future dark energy studies with clusters and other X-ray selected sources. With the present article, we release the XMM XXL photon and smoothed images along with the corresponding exposure maps.


The cosmic evolution of massive black holes in the Horizon-AGN simulation

Monthly Notices of the Royal Astronomical Society 460 (2016) 2979-2996

M Volonteri, Y Dubois, C Pichon, J Devriendt

© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.We analyse the demographics of black holes (BHs) in the large-volume cosmological hydrodynamical simulation Horizon-AGN. This simulation statistically models how much gas is accreted on to BHs, traces the energy deposited into their environment and, consequently, the back-reaction of the ambient medium on BH growth. The synthetic BHs reproduce a variety of observational constraints such as the redshift evolution of the BH mass density and the mass function. Strong self-regulation via AGN feedback, weak supernova feedback, and unresolved internal processes result in a tight BH-galaxy mass correlation. Starting at z ~ 2, tidal stripping creates a small population of BHs over-massive with respect to the halo. The fraction of galaxies hosting a central BH or an AGN increases with stellar mass. The AGN fraction agrees better with multi-wavelength studies, than single-wavelength ones, unless obscuration is taken into account. The most massive haloes present BH multiplicity, with additional BHs gained by ongoing or past mergers. In some cases, both a central and an off-centre AGN shine concurrently, producing a dual AGN. This dual AGN population dwindles with decreasing redshift, as found in observations. Specific accretion rate and Eddington ratio distributions are in good agreement with observational estimates. The BH population is dominated in turn by fast, slow, and very slow accretors, with transitions occurring at z = 3 and z = 2, respectively.


Raman scattering for intense high orbital angular momentum harmonic generation

2016 Conference on Lasers and Electro-Optics, CLEO 2016 (2016)

J Vieira, RMGM Trines, EP Alves, RA Fonseca, JT Mendonca, R Bingham, P Norreys, LO Silva

© 2016 OSA.We identify a mechanism, based on Raman scattering, to endow near-infrared laser beams with high orders of orbital angular momentum (OAM). In combination with high-harmonic generation, this could lead to very high OAM harmonics in the soft x-ray region.


LOWERING ICECUBE'S ENERGY THRESHOLD for POINT SOURCE SEARCHES in the SOUTHERN SKY

Astrophysical Journal Letters 824 (2016)

MG Aartsen, K Abraham, M Ackermann, J Adams, JA Aguilar, M Ahlers, M Ahrens, D Altmann, K Andeen, T Anderson, I Ansseau, G Anton, M Archinger, C Arguelles, TC Arlen, J Auffenberg, X Bai, SW Barwick, V Baum, R Bay, JJ Beatty, JB Tjus, KH Becker, S Benzvi, P Berghaus, D Berley, E Bernardini, A Bernhard, DZ Besson, G Binder, D Bindig, M Bissok, E Blaufuss, S Blot, DJ Boersma, C Bohm, M Börner, F Bos, D Bose, S Böser, O Botner, J Braun, L Brayeur, HP Bretz, A Burgman, N Buzinsky, J Casey, M Casier, E Cheung, D Chirkin, A Christov, K Clark, L Classen, S Coenders, GH Collin, JM Conrad, DF Cowen, AHC Silva, J Daughhetee, JC Davis, M Day, JPAMD André, CD Clercq, EDP Rosendo, H Dembinski, SD Ridder, P Desiati, KDD Vries, GD Wasseige, MD With, T Deyoung, JC Daz-Vélez, VD Lorenzo, H Dujmovic, JP Dumm, M Dunkman, B Eberhardt, T Ehrhardt, B Eichmann, S Euler, PA Evenson, S Fahey, AR Fazely, J Feintzeig, J Felde, K Filimonov, C Finley, S Flis, CC Fösig, T Fuchs, TK Gaisser, R Gaior, J Gallagher, L Gerhardt, K Ghorbani, L Gladstone

© 2016. The American Astronomical Society. All rights reserved.Observation of a point source of astrophysical neutrinos would be a "smoking gun" signature of a cosmic-ray accelerator. While IceCube has recently discovered a diffuse flux of astrophysical neutrinos, no localized point source has been observed. Previous IceCube searches for point sources in the southern sky were restricted by either an energy threshold above a few hundred TeV or poor neutrino angular resolution. Here we present a search for southern sky point sources with greatly improved sensitivities to neutrinos with energies below 100 TeV. By selecting charged-current ν μ interacting inside the detector, we reduce the atmospheric background while retaining efficiency for astrophysical neutrino-induced events reconstructed with sub-degree angular resolution. The new event sample covers three years of detector data and leads to a factor of 10 improvement in sensitivity to point sources emitting below 100 TeV in the southern sky. No statistically significant evidence of point sources was found, and upper limits are set on neutrino emission from individual sources. A posteriori analysis of the highest-energy (∼100 TeV) starting event in the sample found that this event alone represents a 2.8σ deviation from the hypothesis that the data consists only of atmospheric background.


Suppression of phase mixing in drift-kinetic plasma turbulence

Physics of Plasmas American Institute of Physics (AIP) (2016)

JT Parker, EG highcock, AA schekochihin, PJ Dellar


Review of particle physics

Chinese Physics C 40 (2016)

C Patrignani, K Agashe, G Aielli, C Amsler, M Antonelli, DM Asner, H Baer, S Banerjee, RM Barnett, T Basaglia, CW Bauer, JJ Beatty, VI Belousov, J Beringer, S Bethke, H Bichsel, O Biebel, E Blucher, G Brooijmans, O Buchmueller, V Burkert, MA Bychkov, RN Cahn, M Carena, A Ceccucci, A Cerri, D Chakraborty, MC Chen, RS Chivukula, K Copic, G Cowan, O Dahl, G D'Ambrosio, T Damour, D De Florian, A De Gouvêa, T DeGrand, P De Jong, G Dissertori, BA Dobrescu, M D'Onofrio, M Doser, M Drees, HK Dreiner, DA Dwyer, P Eerola, S Eidelman, J Ellis, J Erler, VV Ezhela, W Fetscher, BD Fields, B Foster, A Freitas, H Gallagher, L Garren, HJ Gerber, G Gerbier, T Gershon, T Gherghetta, AA Godizov, M Goodman, C Grab, AV Gritsan, C Grojean, DE Groom, M Grünewald, A Gurtu, T Gutsche, HE Haber, K Hagiwara, C Hanhart, S Hashimoto, Y Hayato, KG Hayes, A Hebecker, B Heltsley, JJ Hernández-Rey, K Hikasa, J Hisano, A Höcker, J Holder, A Holtkamp, J Huston, T Hyodo, K Irwin, JD Jackson

© 2016 Regents of the University of California.The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,062 new measurements from 721 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Among the 117 reviews are many that are new or heavily revised, including those on Pentaquarks and Inflation. The complete Review is published online in a journal and on the website of the Particle Data Group (http://pdg.lbl.gov). The printed PDG Book contains the Summary Tables and all review articles but no longer includes the detailed tables from the Particle Listings. A Booklet with the Summary Tables and abbreviated versions of some of the review articles is also available.


THE FIRST COMBINED SEARCH for NEUTRINO POINT-SOURCES in the SOUTHERN HEMISPHERE with the ANTARES and ICECUBE NEUTRINO TELESCOPES

Astrophysical Journal 823 (2016)

S Adrián-Martínez, A Albert, M André, G Anton, M Ardid, JJ Aubert, B Baret, J Barrios-Martí, S Basa, V Bertin, S Biagi, R Bormuth, MC Bouwhuis, R Bruijn, J Brunner, J Busto, A Capone, L Caramete, J Carr, T Chiarusi, M Circella, R Coniglione, H Costantini, P Coyle, A Creusot, I Dekeyser, A Deschamps, G De Bonis, C Distefano, C Donzaud, D Dornic, D Drouhin, A Dumas, T Eberl, D Elsässer, A Enzenhöfer, K Fehn, I Felis, P Fermani, F Folger, LA Fusco, S Galatà, P Gay, S Geißelsöder, K Geyer, V Giordano, A Gleixner, R Gracia-Ruiz, K Graf, S Hallmann, H Van Haren, AJ Heijboer, Y Hello, JJ Hernández-Rey, J Hößl, J Hofestädt, C Hugon, CW James, MD Jong, M Kadler, O Kalekin, U Katz, D Kießling, P Kooijman, A Kouchner, M Kreter, I Kreykenbohm, V Kulikovskiy, R Lahmann, D Lefèvre, E Leonora, S Loucatos, M Marcelin, A Margiotta, A Marinelli, JA Martínez-Mora, A Mathieu, T Michael, P Migliozzi, A Moussa, C Mueller, E Nezri, GE PǍvǍlaş

© 2016. The American Astronomical Society. All rights reserved.We present the results of searches for point-like sources of neutrinos based on the first combined analysis of data from both the ANTARES and IceCube neutrino telescopes. The combination of both detectors, which differ in size and location, forms a window in the southern sky where the sensitivity to point sources improves by up to a factor of 2 compared with individual analyses. Using data recorded by ANTARES from 2007 to 2012, and by IceCube from 2008 to 2011, we search for sources of neutrino emission both across the southern sky and from a preselected list of candidate objects. No significant excess over background has been found in these searches, and flux upper limits for the candidate sources are presented for E -2.5 and E -2 power-law spectra with different energy cut-offs.


Turbulent dynamo in a collisionless plasma.

Proceedings of the National Academy of Sciences of the United States of America 113 (2016) 3950-3953

F Rincon, F Califano, AA Schekochihin, F Valentini

Magnetic fields pervade the entire universe and affect the formation and evolution of astrophysical systems from cosmological to planetary scales. The generation and dynamical amplification of extragalactic magnetic fields through cosmic times (up to microgauss levels reported in nearby galaxy clusters, near equipartition with kinetic energy of plasma motions, and on scales of at least tens of kiloparsecs) are major puzzles largely unconstrained by observations. A dynamo effect converting kinetic flow energy into magnetic energy is often invoked in that context; however, extragalactic plasmas are weakly collisional (as opposed to magnetohydrodynamic fluids), and whether magnetic field growth and sustainment through an efficient turbulent dynamo instability are possible in such plasmas is not established. Fully kinetic numerical simulations of the Vlasov equation in a 6D-phase space necessary to answer this question have, until recently, remained beyond computational capabilities. Here, we show by means of such simulations that magnetic field amplification by dynamo instability does occur in a stochastically driven, nonrelativistic subsonic flow of initially unmagnetized collisionless plasma. We also find that the dynamo self-accelerates and becomes entangled with kinetic instabilities as magnetization increases. The results suggest that such a plasma dynamo may be realizable in laboratory experiments, support the idea that intracluster medium turbulence may have significantly contributed to the amplification of cluster magnetic fields up to near-equipartition levels on a timescale shorter than the Hubble time, and emphasize the crucial role of multiscale kinetic physics in high-energy astrophysical plasmas.


Suppression of phase mixing in drift-kinetic plasma turbulence

Physics of Plasmas 23 (2016)

JT Parker, EG Highcock, AA Schekochihin, PJ Dellar

© 2016 Author(s).Transfer of free energy from large to small velocity-space scales by phase mixing leads to Landau damping in a linear plasma. In a turbulent drift-kinetic plasma, this transfer is statistically nearly canceled by an inverse transfer from small to large velocity-space scales due to "anti-phase-mixing" modes excited by a stochastic form of plasma echo. Fluid moments (density, velocity, and temperature) are thus approximately energetically isolated from the higher moments of the distribution function, so phase mixing is ineffective as a dissipation mechanism when the plasma collisionality is small.


Dynamic X-ray diffraction observation of shocked solid iron up to 170 GPa.

Proc Natl Acad Sci U S A 113 (2016) 7745-7749

A Denoeud, N Ozaki, A Benuzzi-Mounaix, H Uranishi, Y Kondo, R Kodama, E Brambrink, A Ravasio, M Bocoum, JM Boudenne, M Harmand, F Guyot, S Mazevet, D Riley, M Makita, T Sano, Y Sakawa, Y Inubushi, G Gregori, M Koenig, G Morard

Investigation of the iron phase diagram under high pressure and temperature is crucial for the determination of the composition of the cores of rocky planets and for better understanding the generation of planetary magnetic fields. Here we present X-ray diffraction results from laser-driven shock-compressed single-crystal and polycrystalline iron, indicating the presence of solid hexagonal close-packed iron up to pressure of at least 170 GPa along the principal Hugoniot, corresponding to a temperature of 4,150 K. This is confirmed by the agreement between the pressure obtained from the measurement of the iron volume in the sample and the inferred shock strength from velocimetry deductions. Results presented in this study are of the first importance regarding pure Fe phase diagram probed under dynamic compression and can be applied to study conditions that are relevant to Earth and super-Earth cores.


Experimental measurements of the collisional absorption of XUV radiation in warm dense aluminium.

Physical review. E 94 (2016) 023203-

B Kettle, T Dzelzainis, S White, L Li, B Dromey, M Zepf, CL Lewis, G Williams, S Künzel, M Fajardo, H Dacasa, P Zeitoun, A Rigby, G Gregori, C Spindloe, R Heathcote, D Riley

The collisional (or free-free) absorption of soft x rays in warm dense aluminium remains an unsolved problem. Competing descriptions of the process exist, two of which we compare to our experimental data here. One of these is based on a weak scattering model, another uses a corrected classical approach. These two models show distinctly different behaviors with temperature. Here we describe experimental evidence for the absorption of 26-eV photons in solid density warm aluminium (T_{e}≈1 eV). Radiative x-ray heating from palladium-coated CH foils was used to create the warm dense aluminium samples and a laser-driven high-harmonic beam from an argon gas jet provided the probe. The results indicate little or no change in absorption upon heating. This behavior is in agreement with the prediction of the corrected classical approach, although there is not agreement in absolute absorption value. Verifying the correct absorption mechanism is decisive in providing a better understanding of the complex behavior of the warm dense state.


Improved limits on dark matter annihilation in the Sun with the 79-string IceCube detector and implications for supersymmetry

Journal of Cosmology and Astroparticle Physics 2016 (2016)

MG Aartsen, K Abraham, M Ackermann, J Adams, JA Aguilar, M Ahlers, M Ahrens, D Altmann, T Anderson, I Ansseau, G Anton, M Archinger, C Arguelles, TC Arlen, J Auffenberg, X Bai, SW Barwick, V Baum, R Bay, JJ Beatty, JB Tjus, KH Becker, E Beiser, S Benzvi, P Berghaus, D Berley, E Bernardini, A Bernhard, DZ Besson, G Binder, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, M Börner, F Bos, D Bose, S Böser, O Botner, J Braun, L Brayeur, HP Bretz, N Buzinsky, J Casey, M Casier, E Cheung, D Chirkin, A Christov, K Clark, L Classen, S Coenders, GH Collin, JM Conrad, DF Cowen, AHC Silva, M Danninger, J Daughhetee, JC Davis, M Day, JPAM De André, CD Clercq, EDP Rosendo, H Dembinski, SD Ridder, P Desiati, KD De Vries, G De Wasseige, M De With, T Deyoung, JC Díaz-Vélez, V Di Lorenzo, JP Dumm, M Dunkman, B Eberhardt, J Edsjö, T Ehrhardt, B Eichmann, S Euler, PA Evenson, S Fahey, AR Fazely, J Feintzeig, J Felde, K Filimonov, C Finley, S Flis, CC Fösig, T Fuchs, TK Gaisser, R Gaior, J Gallagher, L Gerhardt, K Ghorbani

We present an improved event-level likelihood formalism for including neutrino telescope data in global fits to new physics. We derive limits on spin-dependent dark matter-proton scattering by employing the new formalism in a re-analysis of data from the 79-string IceCube search for dark matter annihilation in the Sun, including explicit energy information for each event. The new analysis excludes a number of models in the weak-scale minimal supersymmetric standard model (MSSM) for the first time. This work is accompanied by the public release of the 79-string IceCube data, as well as an associated computer code for applying the new likelihood to arbitrary dark matter models.


Searches for relativistic magnetic monopoles in IceCube

EUROPEAN PHYSICAL JOURNAL C 76 (2016) ARTN 133

MG Aartsen, K Abraham, M Ackermann, J Adams, JA Aguilar, M Ahlers, M Ahrens, D Altmann, T Anderson, I Ansseau, M Archinger, C Arguelles, TC Arlen, J Auffenberg, X Bai, SW Barwick, V Baum, R Bay, JJ Beatty, JB Tjus, K-H Becker, E Beiser, ML Benabderrahmane, P Berghaus, D Berley, E Bernardini, A Bernhard, DZ Besson, G Binder, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, M Boerner, F Bos, D Bose, S Boeser, O Botner, J Braun, L Brayeur, H-P Bretz, N Buzinsky, J Casey, M Casier, E Cheung, D Chirkin, A Christov, K Clark, L Classen, S Coenders, DF Cowen, AHC Silva, J Daughhetee, JC Davis, M Day, JPAM de Andre, C De Clercq, EDP Rosendo, H Dembinski, S De Ridder, P Desiati, KD de Vries, G de Wasseige, M de With, T DeYoung, JC Diaz-Velez, V di Lorenzo, JP Dumm, M Dunkman, B Eberhardt, T Ehrhardt, B Eichmann, S Euler, PA Evenson, S Fahey, AR Fazely, J Feintzeig, J Felde, K Filimonov, C Finley, T Fischer-Wasels, S Flis, C-C Foesig, T Fuchs, TK Gaisser, R Gaior, J Gallagher, L Gerhardt, K Ghorbani, D Gier, L Gladstone, M Glagla, T Gluesenkamp, A Goldschmidt, G Golup, JG Gonzalez, D Gora, D Grant, Z Griffith, A Gross, C Ha, C Haack, AH Ismail, A Hallgren, F Halzen, E Hansen, B Hansmann, K Hanson, D Hebecker, D Heereman, K Helbing, R Hellauer, S Hickford, J Hignight, GC Hill, KD Hoffman, R Hoffmann, K Holzapfel, A Homeier, K Hoshina, F Huang, M Huber, W Huelsnitz, PO Hulth, K Hultqvist, S In, A Ishihara, E Jacobi, GS Japaridze, M Jeong, K Jero, M Jurkovic, A Kappes, T Karg, A Karle, M Kauer, A Keivani, JL Kelley, J Kemp, A Kheirandish, J Kiryluk, J Klaes, SR Klein, G Kohnen, R Koirala, H Kolanoski, R Konietz, L Koepke, C Kopper, S Kopper, DJ Koskinen, M Kowalski, K Krings, G Kroll, M Kroll, G Krueckl, J Kunnen, N Kurahashi, T Kuwabara, M Labare, JL Lanfranchi, MJ Larson, M Lesiak-Bzdak, M Leuermann, J Leuner, L Lu, J Luenemann, J Madsen, G Maggi, KBM Mahn, M Mandelartz, R Maruyama, K Mase, HS Matis, R Maunu, F McNally, K Meagher, M Medici, A Meli, T Menne, G Merino, T Meures, S Miarecki, E Middell, L Mohrmann, T Montaruli, R Morse, R Nahnhauer, U Naumann, G Neer, H Niederhausen, SC Nowicki, DR Nygren, AO Pollmann, A Olivas, A Omairat, A O'Murchadha, T Palczewski, H Pandya, DV Pankova, L Paul, JA Pepper, CP de los Heros, C Pfendner, D Pieloth, E Pinat, J Posselt, PB Price, GT Przybylski, J Puetz, M Quinnan, C Raab, L Raedel, M Rameez, K Rawlins, R Reimann, M Relich, E Resconi, W Rhode, M Richman, S Richter, B Riedel, S Robertson, M Rongen, C Rott, T Ruhe, D Ryckbosch, L Sabbatini, H-G Sander, A Sandrock, J Sandroos, S Sarkar, K Schatto, F Scheriau, M Schimp, T Schmidt, M Schmitz, S Schoenen, S Schoeneberg, A Schoenwald, L Schulte, L Schumacher, D Seckel, S Seunarine, D Soldin, M Song, GM Spiczak, C Spiering, M Stahlberg, M Stamatikos, T Stanev, A Stasik, A Steuer, T Stezelberger, RG Stokstad, A Stoessl, R Strom, NL Strotjohann, GW Sullivan, M Sutherland, H Taavola, I Taboada, J Tatar, S Ter-Antonyan, A Terliuk, G Tesic, S Tilav, PA Toale, MN Tobin, S Toscano, D Tosi, M Tselengidou, A Turcati, E Unger, M Usner, S Vallecorsa, J Vandenbroucke, N van Eijndhoven, S Vanheule, J van Santen, J Veenkamp, M Vehring, M Voge, M Vraeghe, C Walck, A Wallace, M Wallraff, N Wandkowsky, C Weaver, C Wendt, S Westerhoff, BJ Whelan, K Wiebe, CH Wiebusch, L Wille, DR Williams, H Wissing, M Wolf, TR Wood, K Woschnagg, DL Xu, XW Xu, Y Xu, JP Yanez, G Yodh, S Yoshida, M Zoll

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